History of Dujiangyan

Planning

During the Warring States period, people who lived along the banks of the Min River were plagued by annual flooding. Qin governor, irrigation engineer, and hydrologist Li Bing investigated the problem and discovered that the river was swelled by fast flowing spring melt-water from the local mountains that burst the banks when it reached the slow moving and heavily silted stretch below.

One solution would have been to build a dam but Li Bing had also been charged with keeping the waterway open for military vessels to supply troops on the frontier, so instead he proposed to construct an artificial levee to redirect a portion of the river’s flow and then to cut a channel through Mount Yulei to discharge the excess water upon the dry Chengdu Plain beyond.

Construction

Li Bing received 100,000 taels of silver for the project from King Zhao of Qin and set to work with a team said to number tens of thousands. The levee was constructed from long sausage-shaped baskets of woven bamboo filled with stones known as Zhulong held in place by wooden tripods known as Macha. The construction of a water-diversion levee resembling a fish’s mouth took four years to complete.

Cutting the channel proved to be a far greater problem, as the tools available to Li Bing at the time, before gunpowder was invented, could not penetrate the hard rock of the mountain, so he used a combination of fire and water to heat and cool the rocks until they cracked and could be removed. After eight years of work, a 20-metre-wide (66 ft) channel had been gouged through the mountain.

Legacy

After the system was finished, no more floods occurred. The irrigation made Sichuan the most productive agricultural region in China. On the east side of Dujiangyan, people built a shrine in remembrance of Li Bing.

Li Bing’s construction is also credited with giving the people of the region a laid-back attitude to life; by eliminating disaster and ensuring a regular and bountiful harvest, it has left them with plenty of free time.

In 2000, Dujiangyan became a UNESCO World Heritage Site. Today it has become a major tourist attraction in Sichuan.

2008 Sichuan earthquake
On May 12, 2008 a massive earthquake struck a vast portion of west Sichuan, including the Dujiangyan area. Initial reports indicated that the Yuzui Levee was cracked but not severely damaged. Diversion of flow could still be seen as the river turns.

Source From: https://en.wikipedia.org/wiki/Dujiangyan#History